1. Field of the Invention
The present invention relates to an apparatus for holding a slider during the threading of a slide fastener chain through the slider in the manufacture of a slide fastener.
2. Description of Prior Art
Most of slide fastener sliders include a slider body and a pull tab pivotally connected to the slider body and having an aperture. Various apparatus are known which automatically hold such a slider upside down for threading therethrough of a slide fastener chain in the manufacture of a slide fastener.
A prior art apparatus as disclosed in U.S. Pat. No. 3,902,235, issued Sept. 2, 1987 includes a vertically movable holder body having at its upper end a slider seat with an upwardly opening slit and a spring-biased pivotable lever having a locking projection. To hold a slider, the holder body is moved upwardly toward the slider until the slider's pull tab is longitudinally received in the slit and then the slider body is supported on the slider seat, in response to which the lever is actuated to turn so that the locking projection projects into the slit for engagement with the edge of the aperture in the pull tab.
Another prior art apparatus as disclosed in U.S. Pat. No. 4,437,233, issued Mar. 20, 1984 includes a holder body having at its upper end a slider seat and defining adjacent to the slider seat an upwardly opening space that is also opening toward a slider chute. A slider is fed from the chute horizontally to the apparatus until the slider body is supported on the slider seat, during which time the pull tab hanging from the slider body is introduced into the space and is then engaged by a locking projection of a spring-biased pivotable lever.
However, these prior art apparatus have the following disadvantages due to the fact that the pull tab is subject to objectionable vibration during operation: With the first-mentioned apparatus, the slider seat frequently fails to receive the pull tab in the slit, so that the slider can inevitably fall off the seat as the holder body is moved upwardly. With the second-mentioned apparatus, the locking projection of the lever tends to inadequately engage the edge of the aperture in the pull tab, and hence firm holding of the slider is difficult to achieve. As a result, the slider can be easily detached from the holder body during the threading of a slide fastener chain through the slider.